It's an office building and Suite 300 appears to be a shared office suite. Suite 300 is also the address for Beacon Hill Staffing Group, EG Communications Group, Regus/HQ, DiTocco Law Group, PLLC (Tony DiTocco is a bankruptcy lawyer), and THE RUSSELL LAW FIRM, P.L., and probably other companies. Here are other businesses in the building, per Google Maps: